Grain treating apparatuses and processes of operation thereof

ABSTRACT

A shell assembly, an agitating and transport drum assembly and a heating assembly adjusted to a non-oxidizing flame provide inexpensive yet reliable and safe grain drying: a multi-element scooped drum assembly provides improved contact of the heating gases and the solid particulate material.

United States Patent 1191 Triplett June 26, 1973 GRAIN TREATING APPARATUSES AND PROCESSES OF OPERATION THEREOF [76] Inventor: Lloyd WITriplett, mute T, tiauae,

Tex. 790l9' 22 Filed: Dec. 27, 1971 21 Appl. No.: 212,131

[52] U.S. Cl. 432/105 [51] Ill. CI. F27b 7/00 [58] Field OI Search 263/32, 33; 34/166;

[56] References Cited UNITED STATES PATENTS 3,245,154 4/1966 Bojr1eret 1. 263/33R 1/1968 Nielsen .Q 263/3311 9/1971 Watson eta]. ..263/33R Primary Examiner-John J. Camby Attorney-Ely Silverrnan [57] ABSTRACT A shell assembly, an agitating and transport drum assembly and a heating assembly adjusted to a nonoxidizing flame provide inexpensive yet reliable and safe grain drying: a multi-element scooped drum assembly provides improved contact of the heating gases and the solid particulate material.

5 Claims, 1.0 Drawing Figures PAIENTEDauusma 3.741.117

SHEET 1 BF 3 LLOYD M TR/PLETT PATENIEDJUIIZB m 3.741.717

SHEET 2 0? 3 wumm 258 LLOYD M TR/ LETT GRAIN TREATING APPARATUSES AND PROCESSES OF OPERATION THEREOF BACKGROUND OF THE INVENTION 1. Field of the Invention The field of art to which the invention pertains are, in Foods and Beverages, processes of cereal puffing; in drying and gas or vapor contact with solids apparatus with axially rotary drums foramenous distributors and countercurrent flow and processes with treated material motion.

2. Description of the Prior Art Grain drying apparatuses using flame to develop heat to dry out moist grain involve fire risk and suffer from poor heat transfer from heating gas to heated grain particle.

SUMMARY OF THE INVENTION In use of concentric drums, perforated to improve heat transfer and helically corrugated to expedite longitudinal movement of the to-be-treated solid, a nonoxidizing gas is provided with location of the zones for heating the treating gas spatially removed from the path of heated grain and related material and a multisectioned drum shape is used to provide a substantially continuous and complete contact of the major portion of heating gas and the to-be-heated solid particles.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic longitudinal vertical sectional view'of one embodiment 20 of apparatus according to this invention.

FIG. 2 is an oblique front and left end view from the left end of the apparatus of FIG. 1.

FIG. 3 is an oblique rear and end view from the right end of the apparatus of FIG. 1.

"FIG. 4 is a schematic longitudinal vertical sectional view of another-embodiment of apparatus, 220, according to this invention. FIG. 4 shows the drum 110 in vertical FIG. 9.

FIG. 5 is a broken away oblique diagrammatic view of thestructures in the zone 5A'5A of FIG. 4.

FIG. 6 is 'an enlarged oblique and sectional view in zone 6A of FIG. 1 of a detail of the drum assembly 70.

FIG. 7 is a perspective view of a portion of the drum assembly of apparatus 220 of FIG. 5 in zone 7A.

FIG. 8 is a diagrammatic sectional view of a burner assembly 140, in zone 8A of FIG. 2 and 8B of FIG. 5.

FIG. 9 is a diagrammatic scale presentation of a longitudinalysection of plane 4A-4A of transverse section through drum 110 rotated counterclockwise 120 (as seen from right side of FIG. 7) from the position shown in FIG. 7.

FIG. 10 diagrammatically illustrates the longitudinal vertical section of another embodiment 230 of this invention.

DESCRIPTION on THE PREFERRED EMBODIMENTS rigid right front vertical pier 27, a straight vertical rigid right rear vertical pier 28 and straight rigid left rear pier 29. The left and right front piers 26 and 27 are joined by rigid straight horizontal beam members; i.e., top front side horizontal beam member 41 and bottom front side horizontal beam member 42. The rear vertical piers 28 and 29 are joined by rigid straight horizontal beam members, top rear side beam member 45 and bottom rear side beam member 46. A rigid triangular left truss 47 is firmly attached to the top of left front pier member 26 and left rear pier member 29 and a rigid right truss 48 is firmly attached to the top of right front pier member 27 and right rear pier member 28. A rigid straight semi-cylindrical, upwardly convex roof crest beam 43 extends from the top of the left truss 47 to the top of the right truss 48.

The walls of assembly 30 are rigid imperforate and insulating and firmly join these frame members and provide rigidity thereto. The left verticalend wall 31 is a rigid plate firmly joined to the left front and left rear piers 26 and 29. The second or right vertical end wall plate 32 is a rigid flat plate joined firmly to the right front pier 27 and the right rear pier 28. A front vertical wall 33 comprises va rigid plate joined to the front horizontal members 41 and 42 and a rear vertical wall .34,

edge of crest member 43 and to front horizontal beam 41 and to the front portions of the left truss 47 and right truss 48. a similar rear roof member 37 is an imperforate rigid insulating plate attached firmly to the bottom rear edge of crest beam 43 and to the top beam member 45 and rear portions of trusses 47 and 48. A first bottom sloped wall section 36 is firmly attached to the front bottom beam 42 and extends downwardly and inwardly therefrom. A rear'bottom sloped-wall section 38 is firmly attached to the rear bottom beam stringer 46 and extends downwardly and inwardly thereof. A shell chamber 40 is located between the walls and sections 31-38. It is within this shell chamber 40 that the agitating and transport assembly 22 is located.

A stack 50 is operatively connected to the chamber 40. That stack chamber is defined by a left vertically extending left wall 51, a vertically extending right wall 52, a front vertically extending wall 53. and a rear vertically extending wall 54. The walls 51-54 are joined at the top by an imperforate top wall 55 and im'perforate, except for the opening of tube 46. An input tube 56 joins the right wall 52. The orifice of that tube 56 joins with the stack chamber. A fan casing 57 is firmly attached to the left wall 51 and supported on the roof 55.

A fan inlet opening 58 is located in the stack roof 55 and a fan outlet'opening 59 is connected thereto. The stack opening 59 connects the shell chamber ,40 to the stack chamber 49.

The agitating and transport assembly 22 comprises an auger assembly 60, an intermediate drum unit 70, an outer drum unit 80, a drive assembly and a discharge assembly 90 and chute supported on the shell assembly 21.

The auger assembly 60 comprises a helical auger blade 61, shaft 62, sprocket 63 and trough 64. The helical fiat blade 61 is firmly attached to a horizontal shaft 62. The shaft in turn is firmly attached to a driven sprocket 63. The sprocket 63 is connected to and driven by a drive chain 69 and serves to rotate the shaft 62. The auger is located above and within imperforate semi-cylindrical trough 64. The auger is provided with rigid flat flights 65 and 66 the lengths of which extend lengthwise of the auger and also, being flat, the widths of each flight extends radially along the width of the auger blade 61 and each flight is affixed to that blade. Shaft 62 is rotatably supported by a right bearing 67 in a right hand wall 32 and on a left bearing 78 in the left vertical shell wall 31. Blade 61 is perforated.

The intermediate drum assembly unit comprises an intermediate hollow drum 71 below described which is supported on a horizontally extending rigid axle 72. The horizontally extending axle 72 has, firmly attached thereto, a driven sprocket 78 at its left end and a drive sprocket 73 at its right end. The axle 72 is rotatably supported on a bearing 75 in the left hand shell wall 31 and in a bearing 76 in the right shell wall 32. Rigid spider frames 74, 74 and 74" are firmly attached to the interior of the intermediate shell 71 and to the axle shaft 72 along the length thereof.

A chute 100 extends downwardly from the upper left wall at level of bottom of auger shaft 62 to below the top of the outer drum 80. Side walls 101 and 102 and end wall 103 define the chute chamber 104; chamber 104 extends from a semi-circular upper chute inlet orifice 105 located in wall 31 above the bottom of shield 64 and below shaft 62 to a chute outlet orifice 106 which extends from above shaft 73 to between'the top and bottom of shell 71.

The outer drum 80 comprises an outer hollow cylindrical shell 81 and a plurality of rigid like spiders 84, 84' and 84" each of which spiders are at one end firmly attached to the interior of the shell 81 and at the other end to the axle 72.

The drums 70 and 80 are concentric; each is formed of a perforated and corrugated steel sheet with corrugation as 107 on sheet70 and 108 on sheet 80 arranged in ahelical form. The helical corrugations extend to the right and downward'on the rear side of the drum 70 and extend in the opposite direction; i.e., to the left and downward on rear side of the outer drum 80.

Each of the intermediate drum 70 and the outer drum 80 is made of corrugated and steel sheet metal 0.060 inches thickness, 117 and 118 respectively, perforated with circular holes as 120 of 0.010 inch diameter extending radially through such sheet. The centers of these holes are arrayed over the sheet of which the drum is formed as equilateral triangles with one-fourth inch between the centers of each of the neighboring holes. The corrugations of the sheet of which the drum is formed are 2% inches between crests of the corrugations and the corrugated sheet measured parallel to the longitudinal axis of the drum and the radial distance from the top of the crest, as 123 and 123 to the bottom surface of the adjacent trough, as 124 of the corrugations is one-half inch, which distance includes the thickness of the sheets as 117. The'shape of the corrugations is that of a sine curve.

The helical crest to helical crest distance of each corrugations is the drum wall along the longitudinal axis of the drum 70 of the helical corrugations is inches in the large drum 80 and a smaller distance about 3 inches in the 24 inch diameter drum 70.

The drive assembly 85 comprises in operative combination an electric motor 86 which drives a main sprocket 87. The main sprocket 97 is operatively connected by a chain drive as 88 to that sprocket and to the drive sprocket 78 on the drum axle 72. The driven sprocket 73 which is firmlyattached to shaft 72 turns with shaft 72 and serves to drive the sprocket 63 on the shaft 62 through the drive chain 69 therebetween and operatively connected thereto and so serves to drive the shaft 62 for auger assembly 60. A drive sprocket 87 on the motor 86 is connected by a drive chain 89 to the drive sprocket 94 of the discharge assembly 90.

The discharge assembly comprises a helical conveyor 91, a chute 93 and a drive sprocket 94. The conveyor 91 operates at the bottom of the'V-shaped chute formed at the bottom of chamber 40 by'the sloped walls 133 and 134. Chute 93 is a semi-cylindrical upwardly concave steel trough: its top edges connect to the bottom of wall 134 and to the bottom of wall 134 and are firmly attached thereto as by welding. Chute 93 is formed of rigid steel imperforate sheets such as are walls 31-35.

The front bottom wall section 36 of shell assembly 21 comprises a front upper heater frame section 132 and a front bottom sloped wall section 134. Some parts of the heating assembly 23 are supported in the upper front heater frame assembly 132. The rear bottom wall section 38 of the shell assembly 21 comprises a rear upper heater frame section 131 and rear bottom sloped wall section 133. Wall sections 133 and 134 are imperforate rigid steel plates. The rear heater frame section 131 shown in FIG. 5 comprises a series of vertical frame elements, as 135 and 137, each of which is firmly attached at its top to the horizontal beam member 46 and at its bottom to the top of the plate 133. A burner plate opening 136 is located between each of the frame members, as 135 and 137, and a burner screen plate 141 is located in such an opening and firmly attached to those frame members. Sections 36 and 38 are the same for embodiments 20 and 220. 4

A plurality of like openings 136A, 1368 and 136C, each like 136, are located in rear upper heater frame section 131 between the top of the plate 133 and the rear beam member 46 within the rear wall section 38 of the shell assembly 21. Front upper heater frame section 132 is a like structure to section 131 for the heater elements and is similarly attached to and located on the front sloped bottom wall section 134 and front side beam member 41 and has similar openings as 136E therein.

The burner screen plates as 142 fill all the openings as 136 and 136E in the bottom wall sections 131 and 132.

The heating assembly 23 comprises 40 like burner assemblies, as A and 1408, twenty in the heater frame elements of rear frame section 131 and twenty in the heater frame elements of front frame section 132. Each burner assembly comprises a porous ceramic burner screen plate 141, a burner connector pipe 142, a gas supply line 143 and an outer flame chamber wall 144. The burner connector 142 is a standard L-shaped sturdy heat resistant cast iron nozzle which connects at its bottom to a gas line 143 in a conventional manner and at its top to the chamber 145 and is attached to wall 144, gas line 143 running the length of chamber 40 on the outside thereof on the front of the chamber 40 and another like line 143A at the rear outside of chamber 40. Each gas line as 143 is connected to a plurality of burner connectors-as 142. Each burner is attached to the rigid outer flame chamber or plenum wall 144.

Wall 144 with the burner screen plate 141 outlines a flame or burning chamber 145. A pilot light 146 may be located in each flame chamber, as 145 to provide ignition as needed in conventional manner or ignition may be effected by a torch at the screen plate 141. The burner screen plate 141 is made of a refractory porous material with holes about 1/16 inch diameter which provides that the flame developed by burning of the gas provided by'each gas line, as 143 provides flame temperatures within the plenum chamber 145 and causes the ceramic screen plate 'to glow red visibly, but avoids the production of any flame within the chamber 40. The screen plate 141 is sufficiently porous that the hot combustion gases formed by the combustion of the gas from line 143 and 143A heat the plate, and also pass through that plate into the, chamber 40.

Each of the 40 burners ,-as 140A burns sufficient gas to provide a total of 2,400 .B.T.U. per hour, or a total of 960,000 BTU. per hour.

The fan 147. which is located in the fan casing 57 is a portion ofthe,heating assembly inasmuch as it provides the draft,thatj'helps draw the hot combustion gases provided by the burning assembly through the po rous plate and through the chamber 40. Fan 147 is operatively connected to a motor 148, l horsepower electric motor. The motor 96 of the drive assembly 95 and "the fan motor 148 are attached to conventional 110 volt A.C. electric power'source. Motor 96 is supported on a frame 96A which sets on ground and the fan 147 is supported in the fan casing 57. Fan 147 provides a vacuum of about 12 inches of water during operation of the assembly 20.

A rigid cylindrical conduit extends from right wall 51 of stack 50 upward and to the right and is open upwards at its right end, at its lower end conduit 151 is open into the stack chamber and firmly fixed to the vertical wall 51.

In operation the grain, e.g., milo, to be treated is fed into the top opening of tube 56 and the fan 158 drives the exhaust moisture laden air, treated and heated as below described, up and 'out of fan outlet 59.

Grain tobe heated falls through stack chamber 49 from the tube 56 into the horizontal helical auger or conveyor blade 61 and into the upwardly open semicylindrical trough 64. The blade 61 is perforated and fits loosely in trough 64. I

The drive assembly 85 drives the sprockets 63 and 73 in a counterclockwise direction as seen from the right. Accordingly the grain added to the trough and auger blade is moved leftward in trough 64 by the rotated helical auger 61 to the left end of the trough 64. At the left end the heated grain falls down the chute 100 and then moves rightward therefrom along the intermediate helically grooved and perforated drum 70, rotated by motor 86, to the rightend thereof; at the right end of drum 70 the heated grain falls to the lowermost or outer rotating perforated drum 80. The grain then moves from the right to the left along the rotated drum 80 and falls downward at the left end thereof. During such longitudinal movement of the grain leftward and rightward of chamber 40 the grain is tumbled and exposed to the hot gases that move through the orifices in the drums 70 and 80 as well as countercurrently of the hot gases passing burning assemblies, as 140 to the fan 147 along the lengths of the drums 70 and 80.

Parallel crushing rolls 158 and 159 each inches in diameter and 18 inches long are rotatably supported in chamber 40 and driven by a roll motor 160 through a drive pulley, as 161, belt 163 and driven pulley 162: the rolls are supported on frames therefor, as 164 and 165, that are firmly attached to the frame 25.

The heated and dried grain that falls from the left end of' drum 80 drops into the slot between rolls 158 and 159 and is crushed and flaked. Because of the removal of water theretofore effected from such grain in the apparatus 20, the grain skin is brittle and the interior thereof is expanded by vaporization of the moisture theretofore entrapped in the grain kernel: on entry of such grain between the surfaces of the driven rolls 158 and 159 there is a popping action due to such entrapped steam in the still highly heated grain kernel; the

resultant rupture of the thus treated grain product allows cycling of all such entrapped steam as a heating agent for other grain particles in the apparatus 20 and, also, allows that during the time of further travel of the thus ruptured grain particle along the discharge conveyor 91 the moisture from such grain particle is discharged from the interior of sac-like particles as well as from the exposed surface of theretofore moist surfaces; such liberated moisture is thus removed from the theretofore unexposed interior surface of such grain particles. The crushed grain passes from between the rolls 158 and 159 to the discharge conveyor 91.

The discharge convey0r9l, driven by the drive chain 89 drives the thus treated grain rightwardly along chute 93 to a discharge spout 169 whereat the treated grain is collected.

The walls and roof members and bottom wall sections of shell 21, with the closure of the burner plate openings 136 by the burner plates form a completely closed chamber except for the small openings for bearings and discharge as at spout 169. The fan 148 accordingly acts effectively to stimulate gas flow through the burner screen plates, as 141. All openings as 136 are completely filled with burners located on frames 131 and 132. Natural gas is used for heat; the burners are set to burn so that the oxygenin the burning air passing through the burner is substantially completely exhausted; i.e.', as exhausted as much as the flame in the burners can provide. Accordingly, a non-oxidizing or reducing hot gas, at a temperature over 400 F., but less than carbonizing temperature moves counter-current to the tumbled grain passing through apparatus 20. The hottest gas and grain portions are at the bottom of apparatus 20; the heating gas becomes successively cooler as it moves in counter-current fashion through the drums 80 and and assembly 60 and out of the stack 50 due to evaporation of moisture from the grain and the relatively low temperature of the grain fed to apparatus 20.

The left to right length of the apparatus 20 is nine feet from the left end of that apparatus to its right end.

The r.p.m. of the drum is 12 rpm. This velocity is sufficient to keep the material in the drum well agitated and provide access of the heating gases thereto. More particularly, the drive motor 86 runs at 1,725 rpm. A pulley wheel 187 provides for about a 10 to l reduction and the gear reducer gives about a l5 to 1 reduction additional for shaft 72.

The trash which is usually found in the grain is found to be carbonized at discharge of the treated grain. Accordingly, there is no oxidizing situation in the system following the burning so that the hot gases are, as above described, substantially non-oxidizing and there is no flame problem by this. This apparatus treats 2 tons of milo per hour, such milo fed has a moisture content of to percent by weight and is discharged at less than 0.03 percent moisture by weight.

The diameter of the drum 70,which is made of the same sheet material as the drum 80, is approximately 24 inches. There is an opening of 6 to 12 inches between the right hand end of the drum 70 and right shell wall 31. The drum' 80 has an end with less than six inches from wall 31.

The shell 21 is 8 feet high at the crest beam 43 (from ground at bottom of piers 25, 26, 27, 28 and 29) and is 42 inches wide from front to rear at its widest point, which is at the level of the axle 72. The bottom of the burner plates are 12 inches below the bottom of the drum 80; the plates 141 are 21 inches high and the outlet of the burner pipe 142 is in the middle of the wall 144: wall 144 and plate 141 are each 6 inches wide: axle 62 is 31 inches above axle 72; sprocket 94 is 52 inches therebelow.

Helical auger blade 61 is perforated with circular holes to allow free flow of heated gas therethrough. The diameter of such holes are about 3 inches and the helix diameter is about 16 inches and certainly provide no obstruction to the flow of hot gas therepast.

This is a low pressure system (as evidenced by the relatively small size of the fan that provides the driving energy for the system). The oxygen content of the gas in the tower is so low that there is no flame near the grain thus treated.

The burner assemblies 140 each have on their internal discharge orifice a ceramic wall 141 with a large number of small perforations. This provides for heating of gas and a heat reservoir but substantially complete destruction of any flame.

In the embodiment of invention 220 (a) the drums 70 .and 80 are substituted for by a drum 110 and (b) the discharge assembly 90 is substituted for by a mesh system290 for'the discharge assembly 90, and (c) the stack 50 is moved from the right hand position on assembly 21 shown in FIG.'1 to the lefthand position shown in FIG. 4 and the helical auger 60 is made with an opposite direction of helix motion.

- In the embodiment 220 the drum 110 is made of 3 semi-cylindrical rigid elements each corrugated and perforated. The corrugations in elements of drum 110 are circular. The shape of the corrugations; i.e., the distance between crests and height of the corrugations are the-same as for elements 70 and 80 and is illustrated also in FIG. 6. The center line 191, 192 and 193 of each of the semi-cylindrical shell elements as'1ll, 112 and 113, respectively is offset from the center line 190, which line is located at the intersection of the diameters of such shells. This offset is along the direction of the diameter of each such shell (as-diametral line from points 171 to 181, from points 172 to 182 and from point 173 to 183 for each of shells 111, 112 and 113, respectively). The amount of this offset is one half the distance of the gap 184, 185 and 186, respectively at each of lips 181, 182 and 183 from the adjacent shells 113, 112 and 111, respectively. The angles that each of these diameters make with each other across the outer line 190 is the'same; i.e., 120 where there are 3 such overlapping elements, as shown in FIGS. 4, 7 and 9. Spiders as 274 and 274', 284 and 284 support the elements 111, 112, 113 on shaft 72.

In the shell structure provided by drums and 80, the perforations 120 provide for some heat transfer by contact of gas and grain particle. However the area of such holes is only 10 percent of the area of the surface of the drums, 70 or and such holes are tangential to the drum sufface. Splitting the drum 70 into several scoop portions as in FIGS. 4 and 7 and 9 provides that gases produced by the burners be positively scooped and pumped into direct contact with all the grain directly rather than through effecting heat transfer through percent of the drum thickness and with the stream of hot gases passing longitudinally through a transverse section of the volume of drums 70 or 80 of which only a portion (of such transverse section) is cocupied by the grain to be heated at any one moment.

The structure of embodiment 220 provides that the at least the major portion of rising column of gas provided by the heating assembly 23 in embodiment 220 is all intercepted by the scoop action of the drum and such interception is accomplished substantially continuously.

As shown in FIG. 9 which is drawn substantially to scale with a 26 inch diameter of drum element 111, 112 and 113 and a 3 inch radial spacing 119, when the drum 110 is sufficiently full, on rotation of that drum in direction 129, two of the three lips, 182 and 181 will usually be blocked by the mass of grain while the third lip 183 would be directing gas tangentially into the mass of grain. With the improved gas liquid contact provided by the drum 110 there is a more uniform heating of the grain independent of the rate of through-put of the treated solid.

The discharge assembly 290 used in embodiment 220 comprises-a mesh or screen support plate 152, an endless flexible metal mesh or screen 153, and drive rollers 154 and 155. The flexible mesh or screen 153 is driven by a motor 65A through the thereby driven mesh drive rollers 154 and. 155. Crushing rolls 258 and 259, corresponding'to rolls 1'58 and '159, are located at the discharge end of the screen 153. The discharge assembly 290 is used when large amounts of stem and leaves and like material (usually referred to as trash") are present in the grain treated: the flexible metal screen 153, which is 1 foot wide and of about 1/16 inch spacing between wires of the mesh serves to clear the plate, 152 therebelow which is 1 foot 2 inches wide as well as transport the heated and dried grain (usually of /s to V4 inch diameter) while the plate 152, which is a smooth flat topped plate supports the grain. The plate 152 is firmly attached to shell frame 25: the walls 133 and 134 extend centrally of the edges of the plate 152 and are attached to the top surface thereof. The jamming effect of trash and any carbonized leaves, stems and the like on helical screw conveyors is thereby avoided. The crushing rolls 258 and 259 are illustrated as located at the discharge end of the screen 153 with a roll hood 260 thereover and flexible rubber strips 261 and 262 that engage the rolls 258 and 259 to prevent entry of air into the chamber 40 within the shell assembly 23 past those rolls which might offset the reducing flame produced by heating assembly 23.

The rolls 258 and 259 are preferably positioned within the chamber 40 as are rolls 158 and 159 to proscope of this invention that the drum assembly 110 be used as shown in FIG. 10, for embodiment 320 with the shell assembly 21 and rolls 158 and 159 of roller assembly 24 in the shell chamber 40 between the discharge of the drum assembly 110 and the discharge conveyor 290 or 90 and operatively connected to drive assembly 85 and heater assembly 23 as above described for embodiment 20 and 220.

In the above description of the apparatuses and process the terms left and right refer to the left and right side of FIGS. 1 and 4, and the term front refers to the side of the apparatuses 20 and 220 closest to the viewer and the term rear refers to the side of such apparatuses distant from the viewer in those figures.

The temperature of the gases exhausted from stack 50 in embodiment 20 is over 150, and about 175 when 2 tons of milo at -15 percent moisture and less than 1 percent trash is fed thereinto and conventional naturalgas of 900 to 1,200 B.T.U./cu.ft. is burned at a sufficient rate of cubic feet per hour to provide 900,000-960,000 B.T.U./hr. by the totality of heating nozzles of heating assembly 23: the flames produced thereby are reducing flames as visually observed by the reflected orange color (of the flame) in the surface of nozzle 142'near the entry thereof into wall 144 and by the absence of any carmelizing odor or burnt smell or appearance of the product at spout 169. The thus flaked and dried milo is'digestible by and palatable to cattle as observed by their consumption and conversion thereof. The exhaust temperature is lower when the drum 110 is used in embodiment, as 220 or 320, than in'embodiment 20.

In the drum 110 the diameter across edge 171 to181 and 172 to 182 and 173 to 183 is 26 inches, each of the gaps 184-185 and 186 is 3 inches measured radially ,from longitudinal axis of the straight rigid cylindrical shaft 72: the drum 110 may be sloped downward onehalf inch per foot towards its discharge end along length of shell assembly 21 and its left and right ends extends to one foot of each of end-walls 31 and 32'of shell 21and discharges the'heated grain at its left end into rolls assembly (in embodiment 320) and is fed at the right end by a chute as 100A from the upper preheating auger asse'mbly 60. The tangential exten'i of the lips 181, '182 and 183 of the rigid semi-circular elements as 111, 112 and 113 (past elements 113, 111 and '112, respectively) and loading of drum 110 by mass 175 of grain in segments 111, 112 and 113 is sufficient I to prevent discharge of the material carried by such Q thereto as 112, 113 and 111, respectively. Such action creates smoothly flowing masses or'curtains" of such particulate material I through the inter-particulate spaces of which masses or curtains the hot gases 'produced by the burner assembly 24 is always periodically, regularly, evenly and usually continuously forced by the scoop action of the drum 110 while rotating in the direction (129) of tangential extension of the more radial edges (as 181,182, 183) of that drum (110). Apparatus 20, 220 and 320 may treat other cereal grains than the mile above referred to in the exemplary em-' bodiment of process.

The amount of grain fed to the input 56 is controlled by a variable speed auger 356: this also serves to regulate the grain temperature.

I claim: 1. Apparatus comprising a shell assembly, an agitating and transport assembly, and heating assembly in cooperative combination,

the shell assembly comprising a rigid frame and a plurality of walls with a shell chamber enclosed therein, and, within this shell chamber, the agitating and transport assembly is located, the agitating and transport assembly comprising an anger assembly, an intermediate drum unit, an outer drum unit, a drive assembly and a discharge assembly all supported on the shell assembly, the intermediate drum unit comprising an intermediate hollow drum supported on a horizontally extending rigid axle, the outer drum comprising an outer hollow cylindrical shell, said inner and outer drum being concentric and each formed of a perforated and corrugated steel sheet with corrugation extending in a helical form, said helical corrugations extending to the right and downward on the front side of one drum in the opposite direction on front side of the other drum,

the front bottom wall section of the shell assembly comprising a front upper-heater frame section and a front bottom sloped wall section, a burner and burner screen plate of the heating assembly supported in the heater frame section, and said burner screen plate being made of a refractory porous material which provides that flame developed by burning of gas provides flame temperatures within a plenum chamber but avoids the production of any flame within the shell chamber.

2. Apparatus as in claim 1 comprising crushing rolls in said shell chamber between said outer drum unit and said discharge assembly.

3. Apparatus comprising a shell assembly, an.agitat ing and transport assembly, and'heating asembly in cooperative combination, I

the shell assembly comprising a rigid frameand a plurality of walls with a shell chamber enclosed therein, and, within this shall chamber, the agitating-and transport assembly is located, the shell as-'.

' sembly comprising bottom wall sections,

the agitating and transport assembly comprising an auger assembly, a drum unit, a drive assembly and a discharge assembly all supported on the shellassembly,

the drum unit comprising a plurality of like rigid cylindrical segments the longitudinal central axis of each one of said-segments parallel to said axle and offset radially from said axle in a different direction, one longitudinally extending edge of each of said segments extending radially and tangentially beyond one longitudinally extending edge of another of said segments and another'longitudinally extending edge of each of said segments located centrally of a longitudinally extending edge of another of said segments extending trangentially beyond said another edge. a

4. Apparatus as in claim 3 wherein a bottom wall section of the shell assembly comprises a front upper heater-frame section and a front bottom sloped wall section, a burner and burner screen plate of the'heating assembly supported in the heater frame section below said drum unit and the discharge as-sembly comprises an endlessmesh screen within said shell chamber and and said discharge assembly.

7 l 1 1 I t 

1. Apparatus comprising a shell assembly, an agitating and transport assembly, and heating assembly in cooperative combination, the shell assembly comprising a rigid frame and a plurality of walls with a shell chamber enclosed therein, and, within this shell chamber, the agitating and transport assembly is located, the agitating and transport assembly comprising an auger assembly, an intermediate drum unit, an outer drum unit, a drive assembly and a discharge assembly all supported on the shell assembly, the intermediate drum unit comprising an intermediate hollow drum supported on a horizontally extending rigid axle, the outer drum comprising an outer hollow cylindrical shell, said inner and outer drum being concentric and each formed of a perforated and corrugated steel sheet with corrugation extending in a helical form, said helical corrugations extending to the right and downward on the front side of one drum in the opposite direction on front side of the other drum, the front bottom wall section of the shell assembly comprising a front upper heater frame section and a front bottom sloped wall section, a burner and burner screen plate of the heating assembly supported in the heater frame section, and said burner screen plate being made of a refractory porous material which provides that flame developed by burning of gas provides flame temperatures within a plenum chamber but avoids the production of any flame within the shell chamber.
 2. Apparatus as in claim 1 comprising crushing rolls in said shell chamber between said outer drum unit and said discharge assembly.
 3. Apparatus comprising a shell assembly, an agitating and transport assembly, and heating asembly in cooperative combination, the shell assembly comprising a rigid frame and a plurality of walls with a shell chamber enclosed therein, and, within this shell chamber, the agitating and transport assembly is located, the shell assembly comprising bottom wall sections, the agitating and transport assembly comprising an auger assembly, a drum unit, a drive assembly and a discharge assembly all supported on the shell assembly, the drum unit comprising a plurality of like rigid cylindrical segments the longitudinal central axis of each one of said segments parallel to said axle and offset radially from said axle in a different direction, one longitudinally extending edge of each of said segments extending radially and tangentially beyond one longitudinally extending edge of another of said segments and another longitudinally extending edge of each of said segments located centrally of a longitudinally extending edge of another of said segments extending trangentially beyond said another edge.
 4. Apparatus as in claim 3 wherein a bottom wall section of the shell assembly comprises a front upper heater frame section and a front bottom sloped wall section, a burner and burner screen plate of the heating assembly supported in the heater frame section below said drum unit and the discharge as-sembly comprises an endless mesh screen within said shell chamber and operatively connected to drive means therefor, and a smooth plate below and slidably supporting said screen.
 5. Apparatus as in claim 4 comprising crushing means in said shell chamber between said drum unit and said discharge assembly. 